To be honest this is not a surprise to me. They want Steem(it) was promoted was only to attract the writers/bloggers.
They never really cared about plagiarism, originality.

This is business and advertisement is lying, a way to sell.
Steemit inc will not win the game, it is not better as Facebook. They forgot about their users, the bloggers/writers while focussed on their earnings.

I agree there should be opt-out and it is better to post elsewhere first. Many posts contain links so a snippet here with a link to your own side is fine enough. Plus you can mention is was published elsewhere first.

I am sorry to hear your earnings changed drastically. It will be one of the reasons why so many left. @fitinfunfood mentioned something about it in one of her posts.
I only invested here, thanks for waking me up.

Happy Friday 💕